Beyond the red planet Mars and past the mighty gas giants, a frozen world can be found, a
world that has captured the hearts of millions ever since it was discovered more than 90
years ago. This is a short but true story about the extraordinary
man that discovered the icy dwarf planet that we call, Pluto.
Born on February 4th 1906, Clyde Tombaugh was raised in Streator, Illinois.
In 1922, at the age of 16, his family moved to a farm near Burdett, Kansas with the hope
of starting a bountiful life on a new plot of land.
From a young age, it seems that Tombaugh had a keen interest in astronomy, something that
was encouraged by his family and it is reported that his interest really took hold after he
peered through his uncle's telescope and closely observed parts of the cosmos for the first
time. Unimpressed with store purchased telescopes,
however, at just 20 years old Tombaugh taught himself how to build his own, from hand-ground
mirrors and parts of farming equipment. Over the course of his life, Tombaugh impressively
built more than 30 telescopes by himself, but it was in 1928 when he successfully made
detailed observations of Mars and Jupiter that his path in astronomy really began to
take shape. Tombaugh sent his surprisingly detailed drawings
of Mars and Jupiter to the Lowell observatory in Flagstaff, Arizona hoping that the astronomers
there would provide him with feedback. The drawings impressed the Lowell observatory
director so much, however, that he was offered a position as an amateur astronomer and groundskeeper
instead, occasionally allowing Tombaugh to operate the observatories new photographic
telescope in search of, among other things, the mysterious Planet X.
Back in the 19th century, Many years before Tombaigh had ever begun his search for Pluto,
astronomers thought of Uranus, as the outermost planet in the solar system. But they also
believed that something was gravitationally disturbing Uranus's orbit, and so concluded
that there must be an undiscovered eighth planet.
In 1846 Neptune was mathematically predicted and then observed with telescopes, proving
that there are still undiscovered objects in the outer solar system. Yet the mystery
of Uranus's orbit wasn't solved. As further observations indicated that the ice giant
was perhaps being influenced by yet another large object, beyond Neptune. And so the hunt
for the so-called Planet X began. When Tombaugh was hired back in 1929 he joined
the search for the elusive Planet X, by using the observatories camera-equipped telescope
that could capture two photographs of the same patch of sky on different days. Then
with the help of a device called a blink comparator, Tombaugh compared the photographs, allowing
him to see if any noticeable changes in the star patterns had occurred.
Stars and galaxies essentially remain in the same position in the images, but any bright
objects that are closer, such as planets orbiting the sun could be visually identified by there
motion across the sky. However, these unidentified objects are not easy to pick out, as each
photograph would be covered with sometimes millions of dots of light and so it took Tombaugh
up to a week to examine every pair of exposures. Despite this repetitive challenge, eventually,
he did spot a change, because, after 10 months of searching the night's sky, a large previously
unidentified mass within our solar system moving in front of the distant stars was discovered
beyond Neptune. These are the original photographic plates
dated from January 23rd 1930 and January 29th 1930 that reveal Clyde Tombaugh's discovery,
an object that at the time was considered the solar systems ninth planet and the mysterious
Planet X. Just like the other eight planets in the solar
system, the newly discovered Planet X required an official name, and so staff at the observatory
opened up a worldwide call for suggestions. The best came from 11 year old, Venetia Burney
of Oxford, England, who thought that the icy planet should be named Pluto, after the Roman
god of the underworld. A seemingly suitable name for the solar systems most distant planet.
Unfortunately, not long after Pluto was discovered astronomers realised that the newly found
icy planet was too small to cause the irregularities seen in Uranus's orbit, and so the hunt for
the elusive Planet X once again started. Pluto endured as our solar systems ninth planet
for more than 70 years, before being controversially reclassified as a dwarf planet by the international
astronomical Union in 2006. A change in status that was caused by the discovery of other
Pluto sized objects within a region called the Kuiper belt, the area that Pluto exists
within. Clyde Tombaugh went from being a farmers son
to a promising amateur astronomer and then an internationally famous planet hunter.
Before his death on January 17th 1997, he not only discovered Pluto but was also credited
with the discovery of many galactic clusters, hundreds of asteroids and a comet, among many
other things. But although Tombaugh's life had come to an
end, his journey was only really just beginning. Just 9 years after Tombaugh's passing, NASA
launched the incredible interplanetary probe, New Horizons. A spacecraft that was designed
to fly by Pluto and capture close up images, as well as other scientific data.
New Horizons wasn't on its own, however, as fixed to the inside upper deck of the spacecraft
is a small container holding part of Clyde Tombaugh's ashes, an amazing gesture that
allowed him to travel to his planet. Printed on the container an inscription reads
" Interred herein are remains of American Clyde W. Tombaugh, discoverer of Pluto and
the Solar System's 'third zone'. Adelle and Muron's boy, Patricia's husband, Annette and
Alden's father, astronomer, teacher, punster, and friend: Clyde W. Tombaugh (1906–1997)"
New Horizons successfully passed Pluto and its moons in July 2015 becoming the first
spacecraft ever to visit the distant dwarf planet.
A heartwarming thought, is that Clyde Tombaugh made that long journey and that although he
wasn't able to see the magnificent close up images that were transmitted back to Earth
at the time, a small part of him was instead able to visit Pluto, the dwarf planet that
he discovered and the dwarf planet that revealed its magnificent heart to humanity.